اثر بارگذاری هیدرواستاتیک بر خواص پتروفیزیکی، ژئومکانیکی و ساختاری سنگ مخزن کربناته

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی معدن، پردیس دانشکده‌های فنی، دانشگاه تهران، ایران

2 پردیس پژوهش و توسعه صنایع بالادستی نفت، پژوهشگاه صنعت نفت، ایران

3 گروه مهندسی معدن و نفت دانشگاه نظربایف، آستانا، قزاقستان

10.22078/pr.2019.3563.2627

چکیده

حین تولید از مخازن هیدروکربنی و فرآیند تزریق، تغییرات فشار منفذی باعث تراکم مخزن می‌گردد که منجر به اثرگذاری مستقیم روی خواص پتروفیزیکی سنگ مخزن می‌شود. بنابراین، شناخت تغییرات رفتار سنگ و خواص مخزنی وابسته به تنش مانند تخلخل و نفوذپذیری بسیار با اهمیت است. در این مطالعه، تلاش می‌شود اثر بارگذاری هیدرواستاتیک بر خواص پتروفیزیکی، ژئومکانیکی و ساختاری سنگ مخزن کربناته بررسی شده و تغییرات تخلخل، نفوذپذیری و توزیع اندازه حفرات مورد تجزیه و تحلیل قرار گیرند. جهت بررسی تغییرات صورت گرفته در رفتار ژئومکانیکی سنگ مخزن کربناته، سرعت موج برشی و تراکمی دو نمونه سنگ مخزن با خواص ظاهری و فیزیکی مشابه تحت بارهای مختلف اندازه‌گیری شد. همچنین، به‌منظور بررسی ساختار و تغییرات داخلی نمونه‌های سنگ مخزن از تصاویر میکروسکوپ الکترونی روبشی (SEM) استفاده شد. نتایج حاصل از این مطالعه حاکی از آن است که با افزایش بارگذاری، نفوذپذیری و تخلخل در آخرین مرحله بارگذاری به‌ترتیب 14/36% و 39/7% روند کاهشی از خود نشان می‌دهند. بررسی سرعت‌های موج برشی و تراکمی نشان دادند که با افزایش فشار آنها روند افزایشی داشته و این مسئله ناشی از میزان نسبت حجم فضای ماتریکس سنگ به فضای خالی آن است. تلفیق آنالیز تصاویر SEM و تغییرات اندازه حفرات نشان می‌دهد که در اثر بارگذاری، حفرات ریزتر و متراکم‌تر گشته و میانگین اندازه دانه‌ها کوچک‌تر می‌گردد، که این خردشدن و قرارگیری ذرات ریزتر در میان ذرات درشت‌تر میزان تخلخل و تراوایی را کاهش می‌دهد. شناخت روند تغییرات خواص پتروفیزیکی به‌همراه بررسی تغییرات ساختاری و ژئومکانیکی متناظر آنها در استراتژی‌های تولید از مخازن نفتی و فرآیندهای تخلیه سیالات از مخازن از اهمیت به‌سزایی برخوردار هستند.
 

کلیدواژه‌ها


عنوان مقاله [English]

Effect of Hydrostatic Stress Loading on Petrophysical, Geomechanical and Structural Properties of Carbonate Reservoir Rock

نویسندگان [English]

  • Yaser Salimidelshad 1
  • Ali Moradzadeh 1
  • Ezzatallah Kazemzadeh 2
  • Peyman Pourafshary 3
  • Abbas Majdi 1
1 School of Mining Engineering, College of Engineering, University of Tehran, Iran
2 Upstream Research Center of Petroleum Industry, Research Institute of Petroleum Industry (RIPI), Tehran, Iran
3 epartment of Petroleum Engineering, School of Mining and Geosciences, Nazarbayev University, Astana, Kazakhstan
چکیده [English]

During the production of hydrocarbon reservoirs and the injection process, pore pressure changes lead to reservoir compaction, which directly affects the petrophysical properties of the reservoir rock. Therefore, it is very important to recognize the changes in rock behavior and reservoir properties such as porosity and permeability which are significant. In this study, the effect of hydrostatic loading on petrophysical, geomechanical and structural properties of carbonate reservoir is investigated, which the investigation is followed by analyzing the porosity, permeability and pore size distribution. In order to investigate the changes in the geomechanical behavior of the carbonate reservoir, the compressional and shear wave velocities of two reservoir rock samples with similar geometrical and physical properties have been measured under different loading conditions. Scanning electron microscopy (SEM) images have also been used to examine the structural changes of rock samples. The results of this study show that under loading, permeability and porosity have a decreasing trend in 36.14% and 7.39% respectively in the last loading step. The study of compressional and shear wave velocities demonstrate that there is an increasing trend by increasing pressure, which it is due to the volume ratio of rock matrix to pore space. Combining the analysis of SEM images and pore size distribution shows that pores have become compacted, and the mean pore size has been reduced, in which this pore collapse and the placement of smaller particles among coarse particles have decreased porosity and permeability. Ultimately, understanding the changes in petrophysical properties along with their corresponding structural and geomechanical changes is very important in production planning of hydrocarbon reservoirs.
 

کلیدواژه‌ها [English]

  • Hydrostatic loading
  • Geomechanical Properties
  • Carbonate reservoir rock
  • Microscopic Analysis
  • Sonic Wave Velocity
[1]. Nagel N. B., “Compaction and subsidence issues within the petroleum industry: From Wilmington to Ekofisk and beyond,” Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy, Vol. 26, Issue 1-2, pp. 3-14, 2001. ##

[2]. Karacan C. O., Grader A. S. and Halleck, P. M., “4-D Mapping of porosity and investigation of permeability changes in deforming porous medium,” In SPE Eastern Regional Meeting, Society of Petroleum Engineers, 17-19 October, Canton, Ohio 2001. ##

[3]. Skinner J. T., Tovar F. D. and Schechter D. S., “Computed tomography for petrophysical characterization of highly heterogeneous reservoir rock,” In SPE Latin American and Caribbean Petroleum Engineering Conference, Society of Petroleum Engineers, 2015. ##

[4]. Abdelkarim A. and Abdullatif O., “Combining petrophysical properties and ultrasonic velocity for improved prediction of tight carbonate reservoir,” In Unconventional Resources Technology Conference, Society of Exploration Geophysicists, American Association of Petroleum Geologists, pp. 2201-2207, Society of Petroleum Engineers, Austin, Texas, 24-26, July 2017. ##

[5]. De Assis P., Moraes F., Tabelini R. and Freitas U., “On the influence of texture on ultrasonic velocities of carbonate rocks using a global petrophysical database,” In SEG Technical Program Expanded Abstracts, pp. 3925-3929, Society of Exploration Geophysicists, 2017. ##

[6]. Regnet J. B., Robion P., David C., Fortin J., Brigaud B. and Yven B., “Acoustic and reservoir properties of microporous carbonate rocks: Implication of micrite particle size and morphology,” Journal of Geophysical Research: Solid Earth, Vol. 120, No. 2, pp.790-811, 2015. ##

[7]. Gir R., “Application of sonic waveform attributes in reservoir studies,” Geol. Soc. Malaysia, Bulletin 27, pp. 75-102, 1990. ##

[8]. Baechle G. T., Weger R., Eberli G. P. and Massaferro J. L., “The role of macroporosity and microporosity in constraining uncertainties and in relating velocity to permeability in carbonate rocks,” In SEG Technical Program Expanded Abstracts, Society of Exploration Geophysicists, pp. 1662-1665, 2004. ##

[9]. Weger R. J., Eberli G. P., Baechle G. T., Massaferro J. L. and Sun Y. F., “Quantification of pore structure and its effect on sonic velocity and permeability in carbonates,” AAPG bulletin, Vol. 93, No. 10, pp. 1297-1317, 2009. ##

[10]. Saleh M., Vega S., Prasad M. and Sharma R., “A study of permeability and velocity anisotropy in carbonates,” In SEG Technical Program Expanded Abstracts, pp. 4238-4242, Society of Exploration Geophysicists, 2009. ##

[11]. Vali J., Kazemzadeh E., Aloki B. H. and Esfahani M. R., “The effect of pore geometry on seis mic wave velocities in carbonate rocks from hydrocarbon reservoirs,” Journal of the Earth and Space Physics (JESP), Vol 35, Issue 3, pp. 35-49, 2009. ##

[12]. Baud P., Schubnel A. and Wong T. F., “Dilatancy, compaction, and failure mode in Solnhofen limestone,” Journal of Geophysical Research: Solid Earth, Vol. 105, Issue B8, pp. 19289-19303, 2000. ##

[13]. Rassenfoss S., “Need a faster measure of relative permeability? take a CT scan and follow with digital rock analysis,” Society of Petroleum Engineers. doi:10.2118/0817-0028-JPT, 2017. ##

[14]. Akin S. and Kovscek A. R., “Computed tomography in petroleum engineering research,” Geological Society, London, Special Publications, Vol. 215, No. 1, pp. 23-38, 2003. ##

[15]. Teklu T. W., Zhou Z., Li X. and Abass H., “Experimental investigation on permeability and porosity hysteresis in low-permeability formations,” Society of Petroleum Engineers, doi:10.2118/180226-MS, 2016. ##

[16]. Eberli G. P., Baechle G. T., Anselmetti F. S. and Incze M. L., “Factors controlling elastic properties in carbonate sediments and rocks,” The Leading Edge, Vol. 22, pp. 654-660, 2003. ##

[17]. Aminian K., Bilgesu H. I. and Ameri S., “Influence of pore size distribution on damage profile,” Society of Petroleum Engineers,” doi:10.2118/39587-MS, 1998. ##

[18]. Purcell W., “Capillary pressures-their measurement using mercury and the calculation of permeability therefrom,” Journal of Petroleum Technology, Vol. 1, No. 2, pp. 39-48, 1949. ##

[19]. Rose W. and Bruce W., “Evaluation of capillary character in petroleum reservoir rock,” Journal of Petroleum Technology, Vol. 1, No. 05, pp. 127-142, 1949. ##

[20]. Sriamornsak P. and Thirawong N., “Use of back-scattered electron imaging as a tool for examining matrix structure of calcium pectinate,” International Journal of Pharmaceutics, Vol. 267, Issue 1-2, pp. 151-156, 2003. ##

[21]. Ismail A. R., Jaafar M. Z., Sulaiman W. R. W., Ismail I. and Shiunn N. Y., “Identification of sandstone core damage using scanning electron microscopy,” In AIP Conference Proceedings, Vol. 1901, No. 1, p. 110005. AIP Publishing, 2017. ##

[22]. Wang Q. Z., Li W. and Xie H. P., “Dynamic split tensile test of flattened Brazilian disc of rock with SHPB setup,” Mechanics of Materials, Vol. 41, No. 3, pp. 252-260, 2009. ##

[23]. Gamero-Diaz H., Miller C. K. and Lewis R., “sCore: a mineralogy based classification scheme for organic mudstones,” In SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers, 2013. ##

[24]. Gangi A. F., “Hertz theory applied to the porosity-pressure, permeability-pressure and failure strength-porosity variations of porous rocks,” In The 17th US Symposium on Rock Mechanics (USRMS). American Rock Mechanics Association, 1976. ##

[25]. David C., Wong T. F., Zhu W. and Zhang J., “Laboratory measurement of compaction-induced permeability change in porous rocks: Implications for the generation and maintenance of pore pressure excess in the crust,” Pure and Applied Geophysics, Vol. 143, Issue 1-3, pp. 425-456, 1994. ##

[26]. Ingraham M. D., Bauer S. J., Issen K. A. and Dewers T. A., “Evolution of permeability and Biot coefficient at high mean stresses in high porosity sandstone,” International Journal of Rock Mechanics and Mining Sciences, 96, pp. 1-10, 2017. ##

[27]. Shen P., Li K. and Jia F., “Quantitative description for the heterogeneity of pore structure by using mercury capillary pressure curves,” In International Meeting on Petroleum Engineering, Society of Petroleum Engineers, 1995. ##